This project is proposed: (1) to study the relationship between brain and CSF levels of GABA, amino acids and other related substances of neurochemical interest. These studies comparing the influence of various drugs and surgical procedures on CSF brain GABA levels in animals, will be intended to determine the extent to which analyses of CSF can be beneficial in the diagnosis, treatment and understanding of mental as well as certain neurologic disorders. (2) to measure the levels of GABA and the other components, in CSF of patients with various mental disorders for comparison with that of normal individuals and those with neurologic disorders.